Abstract: An apparatus that can be used to jump-start a car that has a weak battery. It includes a battery booster pack or a battery booster cable that is polarity sensitive and can detect proper and improper connections before providing path for electric current. This apparatus eliminates the danger of reverse connections, shorts, fires, spark firing and battery explosion. The apparatus requires no separate switching mechanism to turn power on or power off. It also does not require the imperfect human judgment of any indication device to determine correct or incorrect connection. The clamps detect for the correct polarity and automatically control the power. Power turns on once a good connection has been made. If user makes a wrong connection, there will be no power but its warning signal will go off. Once a clamp is dislodged from the battery terminal, it automatically turns power off without the need to deactivate a switch.